This invention generally relates to guiding catheters for use in intravascular procedures such as percutaneous transluminal coronary angioplasty (PTCA).
In classic PTCA procedures, a guiding catheter having a preshaped distal tip is percutaneously introduced into the cardiovascular system of a patient and advanced therein until the preshaped distal tip of the guiding catheter is disposed within the aorta adjacent the ostium of the desired coronary artery. The guiding catheter is twisted or torqued from its proximal end which extends out of the patient to turn the distal tip of the guiding catheter so that it can be guided into the coronary ostium. A guidewire and a dilatation catheter having a balloon on the distal end thereof are introduced into and advanced through the guiding catheter to the distal tip thereof, with the guidewire slidably disposed within an inner lumen of the dilatation catheter. The guidewire is first advanced out the distal tip of the guiding catheter, which is seated in the ostium of the patient's coronary artery, until the distal end of the guidewire crosses the lesion to be dilated. The dilatation catheter is then advanced out of the distal tip of the guiding catheter, over the previously advanced guidewire, until the balloon on the distal extremity of the dilatation catheter is properly positioned across the lesion. Once properly positioned, the balloon is inflated to a predetermined size with radiopaque liquid at relatively high pressures (e.g., generally 4-12 atmospheres) to dilate the stenosed region of the diseased artery. The balloon is then deflated so that the dilatation catheter can be removed from the dilated stenosis and blood flow resumed therethrough.
Further details of guiding catheters, dilatation catheters, guidewires, and the like used in angioplasty procedures can be found in U.S. Pat. No. 4,323,071 (Simpson-Robert); U.S. Pat. No. 4,439,185 (Lundquist); U.S. Pat. No. 4,468,224 (Enzmann et al.); U.S. Pat. No. 4,516,972 (Samson); U.S. Pat. No. 4,438,622 (Samson et al.); U.S. Pat. No. 4,554,929 (Samson et al.); U.S. Pat. No. 4,582,185 (Samson); U.S. Pat. No. 4,616,652 (Simpson); U.S. Pat. No. 4,638,805 (Powell); U.S. Pat. No. 4,748,986 (Morrison et al.); and U.S. Pat. No. 4,898,577 (Badger et al.) which are hereby incorporated herein in their entirety by reference thereto.
Guiding catheters are frequently provided with soft distal tips in order minimize trauma to the arterial lining as the guiding catheter is advanced through an arterial passageway. See for example U.S. Pat. No. 4,385,635 (Ruiz) which is incorporated herein by reference. Soft distal tips may reduce arterial trauma, but they do not always provide a smooth transition between the distal tip and the catheter shaft proximal thereto. Additionally, the soft distal tips are very difficult to locate fluoroscopically by the physician when guiding the distal tip into the ostium of the desired coronary artery.
What has been needed and heretofore unavailable is a guiding catheter or other similar catheter with a nontraumatic distal tip which provides a smooth transition with the catheter shaft and is fluoroscopically observable by the physician in order to facilitate the advancement thereof through a patient's vasculature. The present invention satisfies that need.